Ok,
As promised, how to dis-assemble a shay, specifically the HO Bachmann 3-trucker.

First, you&#39;ll need
*a set of screwdrivers (phillips and slotted type),
*a pair of needle nose tweezers,
*a hobby knife with #11 blade, a dull one will do as it comes in handy levering out &#39;push in&#39; parts.
some &#39;Blu-Tac&#39; (locally known product that holds posters to walls that can be peeled off later, sort of a &#39;chewing gum&#39; like substance)

The shay needs to be held upside down in a cradle. If you don&#39;t have one, a block of sponge rubber (like that in chairs and before Woodland Scenics ground it up)with a cut half way through will hold the loco in the cut.
Remove the front and second truck.
Lever out the 2 wiring plugs connecting the tender to the loco.
Remove the drawbar screw and seperate the tender and put it aside.
There are various wire parts that you&#39;ll need to be mindful of, the cab hand rails need to be pulled out of the holes, piping and hand railsin the cab front, sand lines, etc, look around the loco at the various pieces to see what you might need to remove and/or unhook.
Now, study the photo below for screw locations.
The 2 screws labeled 1 hold the ashpan to the chassis.
Screw labeled 2 holds the rear of the cab. It also holds the equalising reservoir under the cab. I forgot to label the screw just to it&#39;s right, behind the rear end of the crankshaft. it&#39;s in plain sight, you just need to look.
Screws 3 hold the bunker to the chassis.
Screw 4 holds the front of the boiler to the chassis. It&#39;s under the power pickup pad which needs to be levered up with the knife. It&#39;s held down by 2 little cast nubs and is only a press fit on.
This is a close up of the boiler screw and pad removed.
Now, you need to gently remove the ashpan but it will have the shay engine attached to it. the engine is also a push fit into a hole in the boiler.
You can see the pins in this view of the rear of the assembly. you can also see the thick white gunk Bachmann feed their engines.
with the ashpan assembly off and safely aside, you need to look for the rear cab screw, under the wiring.
This shot, hopefully will give you an idea where to look. The hole just to the left of my thumb is for the rear ashpan screw.
The boiler, cab and backhead all come off as one piece, just remember the wiring to the headlight. As with most of these parts, a little bit of &#39;wiggling&#39; is needed to unseat them, but any sort of force should be avoided.
You can see how the cab fits to the boiler, there&#39;s really no way of removing it without removing the boiler. The backhead must also go on before refitting the boiler.
I hope I&#39;ve covered everything here, if not let me know and hopefully I can try to clarify things.
This is her after going back together, by reversing the sequence of events. The cross compound compressor can be seen beside the cylanders.
Oh, I forgot to mention that the front truck needs to be tilted up to clear the front coupler before reattaching it (something I forgot, hence theangle on the front truck)

I mentioned I have 3 of these shays, another of which I&#39;d rebuilt with a different superstructure. I aquired a junked brass shay some years ago and kept it in the hope of oneday ressurecting it. It&#39;s now &#39;risen&#39;, thanks to a Bachmann mech under it.
the brass boiler & cab after primer, on the Bachmann running gear.

Recent additional information supplied by Shayman32138 on 13/04/05

Edited PM from Shayman32138
Re: Bachmann shay headlight removal

It appeared that the headlight wires have to be disconnected somehow however I got the boiler off without having to cut any wires. Turns out what was holding it on to the frame was one of the sanding lines (wires) was stuck, probably because of paint. When I popped that loose, I could lift the boiler away from the frame and expose the entire motor. After oiling all the bearings, it was still a little noisy. I discovered that by removing the bearing cap covering the drive shaft, I could better get at the front motor bearing to oil it. That really quieted everything down. It runs so quietly now that I can hear the clicking of the valves and pistons. I also put a drop of Conductalube onto the commutator. I do that on all my open frame motors...makes them run quieter and faster. I finally replaced the old Digitrax decoder with a NCE N12SRP and this Shay runs like a Swiss watch.